Telegraph transmitter



' May 13, 1941. HENNIG 2,241,780

TELEGRAPH TRANSMITTER Filed May 9, 1940 INVENTOR.

FRITZ HENNIG ATTOREY.'

Patented May 13, 1941 UNITED STATES PATENT OFFIQE tion of GermanyApplication May 9, 1940, Serial'No. 334,181 In Germany February 8, 193910 Claims.

This invention pertains to printing telegraph systems and moreparticularly to telegraph systems and apparatus adapted to be operatedunder the control of key levers.

In telegraph systems involving apparatus for recording characters by aseries of elemental areas of positive and negative surfaces,transmitting apparatus has been employed wherein each letter, symbol, orcharacter is analyzed into a succession of constituent areas, and a codeset of corresponding character embodiments are constructed, whichembodiments then are selected under control of a keyboard. In accordancewith suchscanned or analyzed embodiments, electrical impulses aregenerated which cause corresponding operation of recording apparatus ofthe form disclosed in United States Patent No. 2,000,083 to form thecharacters in line.

The principal object of this invention is the provision of a practicaland inexpensive key controlled facsimile telegraph wherein the keyoperations are coordinated cyclically with the transmission of thesignal impulses for each character.

Another object is to provide, in a keyboard controlled facsimiletelegraph transmitter, a means normally operable in regularly recurringcycles to coordinate the operations of a plurality of constan'tlyrotating transmitting elements and a corresponding plurality of keyoperated mechanisms operable in irregularly recurrent cycles.

The above and other objects "of the invention are achieved throughthe'provision of a novel keyboard mechanism for controlling sensingmembers associated with constantly rotating code discs, and timing meansfor coordinating the operations of the keyboard and rotating code discs.An operated key lever controls the selection of a corresponding sensingbrush. Individual to each brush is a code disc designed in accordancewith a method of a prescanning in which the characters or symbols to betransmitted are divided into any desirable number of sensing units orareas. The several unit areas thus created are assigned in order ofscanning to the periphery of the code disc. Inasmuch as the code discsrotate continuously by power communicated thereto from a continuouslyrotating motor and the brushes are selectively operated in accordancewith the operation of the key levers, impulse-s representative of thepositive and negative surfaces of the character code disc will 'betransmitted, which will be effective at the receiving end of the systemto record a character in accordance with the pattern of the characterformed on the periphery of the code disc then effective for thetransmission of the characteristic impulses.

A better understanding of the present invention may be had from thefollowing description taken in conjunction with the accompanying drawingwhich illustrates diagrammatically the keyboard transmitter according tothe present invention, and shows in section a keyboard transmitter inwhich a transmitting drum 24, during its revolution, controls a contact23 for transmitting facsimile signal impulses.

lIhe transmitting drum 24 consists, for example, of insulating materialin which the conducting segments 25 are imbed-ded. Instead of using atransmitting drum in which the segments are formed of metal imbedded ininsulating material, cams may also be used which control thetransmitting contacts, or metal discs, having their peripheries formedas shown in U. S. Patent 2,000,083, may be employed. Upon passing overthese segments, when the contact 23 is in contact with the transmittingdrum 24, a circuit is alternately closed and interrupted so that thecorresponding facsimile signals are sent out. In the axial direction ofthe transmitting drum, are mounted next to each other, the various codeddiscs corresponding to the character signals. The transmitting drum 24consists, for example, of forty different rings or discs, of which oneis shown in section in the illustrated embodiment.

The actuation of key lever l is not dependent upon the position of thetransmitting drum 24, but it may be depressed at any time With respectto the transmitting shaft l 9. The trip member 2 pivotally connected tothe key lever l and biased counterclockwise by spring 21, draws down theholding pawl 3, thereby releasing the corresponding bell crank lever 4.The bell crank lever 4, under the influence of spring 5, is actuatedcounterclockwise, and through the lateral projection 38 thereon pressesthe trip member 2 to the right, against the action of spring 3!, therebydisengaging said member from pawl 3, so that key lever I can no longerafiect holding pawl '3; The counterclockwise rotation of bell crank'l-ever 4 will be permitted because the blocking bar 6 is actuatedleftwardly in timed relation thereto, as will presently appear.

Upon the depression of key lover I, the universal 'bail 1 common to allthe key levers, is actuated against the influence of its spring 28, sothat the pull bar 8 rotates the clutch release lever 9 against theaction of its spring 29, thereby releasing shaft I0, which has a highspeed of roe tation, for a single revolution. The auxiliary I3corresponding to the depressed or operated key lever l. The blocking bar6 is rigidly con, nected to the cam follower lever l2 and, with thelatter, is mounted on the pivot shaft 25.. As a result of thedisplacement of the blocking lever 6 in this manner, all key leversexcept the one depressed are blocked against downward move ment. Theblocking members t3 associated with the key levers l are each normallyheld against the common stop member I4 by individual springs 30, thuswhen the blocking member 6 is deflected lei-twardly upon the operationof a key lever, the member :3 associated with the operated key leverwill be deflected lertwardly. Bell crank member 4, after the lock member3 has been actuated leftwardly, will be rotated counterclockwise by itsspring 5 to bring its shouldered end l5 into engagement with theblocking member 6, thus holding said member 5 in its leftward positionagainst the action of its spring 32. The locking of the keyboard in thismanner is maintained until the character symbol has been transmitted, aswill presently appear. Should the operated key lever be released beforethe signal cycle initiated thereby has been completed, the spring 28will act to lift said key lever to its horizontal or unopera'tedposition, thus bringing notch 45 of bar [3 into engagement with bar 3 toprevent further depression during the present cycle. e

To assure a single revolution of the shaft ID in response to a singleoperation of a key lever I, the lever l2 acts upon a projecting portion40 of lever 3, to actuate said lever 8 counterclockwise against theaction of its spring 36. The upper end of lever 8 is thereby disengagedfrom lever '9 to permit lever 3 to be rotated clockwise by a spring 29to bring said lever 9 into operative engagement with stop disc 42, thuslimiting the rotation of the shaft Iii to one revolution.

While the function described hereinbefore necessarily depends upon thedepression of a key, the transference of the signaling condition, set upby the bell crank lever 4, to the transmitting device is timed by a camcarried upon the continuously revolving transmitting shaft i9. That isto say since the shafts Ill and I3 revolve independently, and in View ofthe fact that a key lever may be operated at any time or instantirrespective of the angular position of the shaft 19 (and hence thetransmitting cylinder 24), nevertheless the transfer of the conditionfrom the key lever portion of the transmitter to the transmitting drumportion is governed by a cam 23 fixed to the shaft E9. The cam 23revolving with the transmitting shaft I9 in the direction of the arrowcontrols, through a roller 2!, carried on lever 43, the control bar 22common to all the bell crank levers 4. Pivotally carried on each bellcrank I4 is a small bell crank lever it might acts, as will presentlyappear, to operate a contact control lever H to permit the engagement ofcontact 23 with transmitting cylinder 24. When the bell crank lever 4 istripped by the operation of lever 3 and is rotated counterclockwise byits spring 5, the bell crank lever 16 is carried rightwardly into closerproximity with the horizontal control bar 22. Thus, when control bar 22is directed to the left (as will presently appear), bell crank lever I6is rotated counterclockwise and then, together with the larger bellcrank lever, 4, is carried along to the left. The end of the horizontalarm of bell crank lever l6 encounters the enlarged end portion l8-of thecontact control lever l1, and

the lever I] is depressed or actuated counterclockwise against theaction of its spring 35. As

a result, the transmitting contact 23 is released by shoulder 34 and,under the influence of spring -35, is rocked about a fulcrum and pin 31and brought into engagement with the transmitting cylinder 24. As thecylinder 24 rotates, a facsimile signal is transmitted which correspondsto'the arrangement of the segments 25 upon the periphery of the portionof the cylinder corresponding to the operated contact 23.

The timing of the transmission of the signal is controlled by cam 20. Asthe cam 20 rotates clockwise, follower roller 2i is first encountered bythe apex 44 of the cam, and lever 43 is accordingly actuated clockwiseagainst the action of its spring 33 so as to cause the bar 22, which iscommon to the contacts 23, to rotate all of the contacts 23counterclockwise against the action of their individual springs 35 tobring the lower ends of said contact members into locking engagementwith their respective shoulders 34 on the contact control levers ll.Immediately thereafter, the follower roller 2! ridesintov the depression45 of cam 20 to cause lever 43 to rotate counterclockwise under theaction of spring 33 so that bar. 22 is actuated leftwardly to rotate allof the bell crank levers 4 clockwise against the action of their springs5 to assure that the lower extremities of thevertical arms of all thebell crank lovers 4 are brought into locking engagement with theirrespective holding pawls 3. If a bell crank lever 4 has been previouslyoperated by a key lever I so that the shoulder I5 is engaged with thelock bar 6, and the small bell crank lever I6 is moved rightwardly, thenjust prior to the restoration of all the bell crank levers 4 totheirlatched or clockwise position, the small bell crank lever l6 of theactuated or operated bell crank lever 4 will be rotated counterclockwiseto impinge its horizontal arm against the end portion I8 to efiect therelease of shoulder 34 from latching engagement with its associatedcontact lever 23. The disengagement of contact lever 23 from shoulder 34occurs at a predetermined instant controlled by cam 25], which instantcoincides with the registration of that portion of the transmittingcylinder ring or periphery indicative of the beginning of the facsimilesignal corresponding to the key lever operated.

The restoration of the bell cranks 4, inclusive of the operated one, tothe latched position (shown in the drawing) by bar 22 will also effectthe disengagement of shoulders [5 from bar 6 to permit bars to bereturned to its rightward position under the influence of spring 32,

paratus, it is manifest that various departures may be made from thedisclosure without departing from the spirit and scope of the invention.

What is claimed is:

1. In a keyboard transmitter for facsimile printing telegraphs, aplurality of transmitting elements, one for each symbol, each having control surfaces corresponding to the light and dark areas of a scannedsymbol, a contact for each transmitting element, a control member foreach contact, a plurality of key levers, one for each contact, meansassociated with each key lever for controlling said control members, andmeans for removing said means from association with said key leversprior to the beginning of transmission of a facsimile system.

2. In a facsimile telegraph system, a transmitter having a plurality oftransmitting elements each having lineally arranged control surfacescorresponding to the light and dark areas of a scanned character, acorresponding plurality of key operated mechanisms, means associatedwith each of said mechanisms for controlling said transmitting elements,and means for removing said means from the influence of said mechanismsprior to the beginning of transmission of a facsimile signal.

3. In a keyboard controlled facsimile telegraph transmitter, a pluralityof transmitting mechanisms, one for each symbol, a correspondingplurality of key operated mechanisms, means for transmitting signalimpulses controlled by said mechanisms, and means for timing theoperation of said transmitting mechanisms independently of the instantof actuation of said key operated mechanisms.

4. In a keyboard controlled facsimile telegraph transmitter, a pluralityof transmitting elements, one for each symbol, a contact for eachelement, a control member for each contact, a corresponding plurality ofkey operated mechanisms, and cam operated means associated with saidelements for timing the operation of said control members independentlyof the instant of actuation of said key operated mechanisms.

5. In a keyboard controlled facsimile telegraph transmitter, a pluralityof keys, a corresponding plurality of transmitting elements, one foreach symbol, said elements being axially arranged and having controlsurfaces corresponding to light and dark areas of a scanned signal, acontact for each element, a control member for each contact, a keyoperated mechanism associated with each control member, and means commonto said mechanisms and said control members and reone for each symbol, acontact moved from the influence of said keys for timing the operationof said control members independently of the time of actuation of saidkey operated mechanisms.

6. In a keyboard controlled facsimile telegraph transmitter, a pluralityof keys, a corresponding plurality of transmitting elements, one foreach symbol, said elements being axially arranged and having controlsurfaces corresponding to light and dark areas of a scanned signal, acontact for each element, a control member for each contact, a keyoperated mechanism associated with each control member, means common tosaid mechanisms and said control members and removed from the influenceof said keys for timing the operation of said control membersindependently of the actuation of said key operated mechanisms, and keylocking means to preclude the premature operation of a succeeding key.

'7. In a keyboard controlled facsimile telegraph transmitter, aplurality of transmitting mechanisms, one for each symbol, acorresponding plurality of key operated mechanisms, and means to controlthe operative relationship between said transmitting mechanisms and saidkey operated mechanisms whereby the transmitting mechanisms are removedfrom the influence of said key operated mechanisms prior to thebeginning of transmission of a facsimile signal.

8. In a keyboard controlled facsimile telegraph transmitter, a pluralityof transmitting mechanisms comprising constantly rotating code elements,a corresponding plurality of key operated start-stop mechanisms, andmeans to coordinate the cyclic operations of said elements and said keyoperated start-stop mechanisms.

9. In a keyboard controlled facsimile telegraph transmitter, a pluralityof transmitting elements, for each element, a control member for eachcontact, a corresponding plurality of key operated mechanisms, and camoperated means associated with said elements for coordinating theoperations of said contact control members and said mechanismsirrespective of the instant of actuation of the latter.

10. In a keyboard controlled facsimile telegraph transmitter, aplurality of transmittin mechanisms comprising constantly rotating codeelements, a corresponding plurality of key operated mechanisms operablein irregularly recur rent cycles, and means normally operable inregularly recurring cycles to coordinate the operations of saidconstantly operable elements and said irregularly operable mechanisms,

FRITZ HENNIG.

